Mobile communication systems were developed to provide the subscribers with voice communication services on the move. With the rapid advance of technologies, the mobile communication systems have evolved to support high speed data communication services beyond the early voice-oriented services.
FIG. 1 is a diagram illustrating a general mobile communication system. Referring to FIG. 1, the mobile communication system includes a User Equipment (UE) 100, a Radio Access Network (RAN) 130, and a core network 140. The RAN 130 may include a few components and, among them, the component 120 which interacts with the UE 100 communicates with the UE 100 through a radio interface 110 and connects to other components of the wireless communication system through wired links. Examples of the RAN component 120 include evolved Node B (eNB), Node B (NB) or Radio Network Subsystem (RNS) including it, Base Transceiver Station (BTS) or Base Station Subsystem (BSS) including it, wireless access point, Home eNB, Home NB, Home eNB GateWay (GW), X2 GW, etc. For the convenience sake, these components or the RAN itself is referred to as radio access point in the following description.
With some exceptions, each of the radio access point 120 is comprised of at least one cell having a predetermined area, and the UE 100 is served by the corresponding radio access point within the cell area. Here, the cell denotes the cell of the general cellular system, and the radio access point 120 is the device of managing and controlling the respective cell but, in the present disclosure, the terms ‘cell’ and ‘radio access point’ are used interchangeably in the same meaning.
In the resource-constrained wireless communication, efficient resource management is one of the most significant issues. In the conventional technology, the information on the UE is retained in or passing only the serving radio access point 120 with some exceptional situation (e.g. right after handover; a radio access point A may have the information on the UE for a predetermined duration after the handover over of the UE from the radio access point A to the radio access point B). Accordingly, the resource management is performed in association with UE mobility management in the conventional technology. This means that there is no need of considering the resource management and the mobility management separately.
When the UE enters the connected state or stays in the connected state, it is possible to perform mobility management through location registration procedure or handover allowance determination. When the UE is in the idle state, UE may initiate mobility management.
If the UE attempts location registration procedure to the radio access point which allows for mobility (if there is no problem in other aspects), the location registration procedure is likely to be successful such that the core network provides the radio access point with the mobility management information. The radio access point is capable of making a handover decision based on this information and, in any case, the source radio access point may send mobility restriction information to the target radio access point. Examples of the mobility management information may include Handover Restriction List (HRL).
If the UE attempts location registration procedure to the radio access point which does not allow for mobility, this procedure is rejected. If the mobility is rejected for the reason of non-allowance of mobility, the message notifying the UE of the rejection may include the cause of the non-allowance of mobility. In this case, the UE may modify, generate, or delete mobility management information under the UE's management based on the cause information. The UE in the idle state is capable of performing mobility management based on the mobility management information.
According to the conventional mobility management-based resource management method (in the case that the information on a UE is retained in or passing one radio access point to which the UE has connected), a specific radio access point may be configured to do not receive the information on a specific UE.
A description is mad of the exemplary case of using the mobility management-based resource management method. The types of small radio access points may be more various than those of the large radio access points and thus there may be a difficulty to verify various types of small radio access points in every case. The unidentified small radio access points are in the state that their security and stability are not verified yet and thus the resource management for the unidentified small radio access points is made integrally with specific information configured for them. For example, a specific unidentified radio access point may be designated with location information restricted to a predetermined UE, e.g. UE carried by a government official, such that the UE of the government official cannot interact with the unidentified small radio access point.
Meanwhile, as the mobile data traffic demand grows, the resource utilization method is being advanced to fulfill the growing mobile data traffic demand. Recently, there is a big change in resource utilization method. Unlike the conventional technology in which one UE interacts with tone radio access point, the recent technology allows one UE to interact with two or more radio access points. In order accomplish this, cooperation at the radio access point level is required.
As an example, the 3rd Generation Partnership Project (3GPP) is planning to deal with the items standardizing the specifications required for realizing the inter-eNB Carrier Aggregation (CA) and inter-eNB Coordinated Multi-Point transmission and reception (CoMP) as the official items of Release 12. Through the standardization of Release 12, the two technologies (inter-eNB CA and inter-eNB CoMP) are to be standardized.
In more detail, the inter-eNB CA is the technology capable of allowing one UE to interact with two or more eNBs using carriers of different frequency bands. In the inter-eNB CA, one Master eNB (MeNB) managing a Primary Cell (PCell) with which the UE interacts primarily and at least one Secondary eNB (SeNB) managing a Secondary Cell (SCell) exist. Since the SeNB (as well as MeNB) is capable of interacting with the UE, the information on the UE may be retained in or passing the SeNB. In the inter-eNB CA, it may be possible for the UE to interact with two or more eNBs using the carriers of overlapped frequency band as well as using the carriers of different frequency bands.
Meanwhile, the CoMP is the technology capable of allowing the eNBs to cooperate for interaction with one UE in order to mitigate the inter-eNB interference caused by using the two or more eNBs using overlapped frequency band. Since the multiple eNBs are capable of exchanging data with one UE in the inter-eNB CoMP like the inter-eNB CA, the information on the UE may be retained in or passing multiple eNBs.
In brief, the inter-eNB CA and inter-eNB CoMP have in common that the information on a UE may be retained in or passing multiple eNBs although some differences exist there between.
This makes it possible to expect that there is a need of change in resource management method depending on the change of resource utilization pattern. The present disclosure proposes a new resource management method.